Yahoo! Clues provides a way to discover and compare trending information. What makes Clues so interesting is that it provides not just search volume charts, but demographic graphs, maps and even related searches to a demographic group. It makes Google Trends look like an elementary-level Excel spreadsheet in comparison.
Noteworthy features include the ability to compare two terms, a time filter (only for the past one, seven and 30 days) and of course the information categories which delve into gender, income, and location.
Yahoo! is also experimenting with a feature called "Search Flow" which offers insights into search patterns and the next most probable search term people try after searching for a query. Also for the search marketers, Yahoo! has provided information on "related searches" - commonly related terms across Yahoo! Search which are not limited to the user search patterns displayed in "Search Flow".
An excellent tool pretty much all the way around - particularly the "Search Flow" data. In the future it would be a good idea for Yahoo! to expand beyond 30 days, so yearly trends can be identified across Yahoo! Search.